Impact of Methylchalcogeno Substitution on the Electronic and Charge Transport Properties of Bis(methylchalcogeno)acenes

The electronic and charge transport properties of a series of methylchalcogeno-substituted acene derivatives are investigated via quantum chemical calculations. To gain a better understanding of the role of methylchalcogeno substitution, the results for bis(methylchalcogeno)anthracene and bis(methylthio)pentacene are compared with those for their parent oligoacenes, that is, anthracene and pentacene. The introduction of methylchalcogeno group can increase the stability of their anionic compounds and lower the injection barriers of electrons in organic electronics devices. The methylchalcogeno group also change the charge transport properties by enhancing pi stacking and chalcogen-chalcogen interactions. The calculations predict that the electron mobilities of bis(methylthio)anthracene and bis(methyltelluro)anthracene are 0.68 and 0.48 cm(2)/(V.s), respectively, which increase by a factor of 2 to 3 with respect to that of anthracene.